I think this is a very interesting thread. I've been wondering so often how many people here just use BDSM to be treated like dirt.
I do think it is a sad story for everyone who has been abused, but I also think when you have a history like that you have a certain responsibility to be honest with your Dom about it. Abused people often can act like there strong and they can handle everything.
I made this mistake myself. I have had a disrespectfull boyfriend and he hurted me a lot. In the beginning of my relationship with my current boyfriend (or now my Master) I thought everything was allright. I mean He respected me, he cared for me, I was save. The problem was, because I felt safe, I remembered my hidden memories and feelings. It triggered me. And just to feel worthless, I used Him. I asked Him to use me, to ignore my feelings. I am so very thankfull that He cared for me and never even thought of using me like that.
We've been talking about it a lot. And we chose not to do kinky stuff, until I was more confident. I worked hard and my Master was helping me so very hard. I will be thankfull for it all my life. At this moment He trusts me when I say it's okay with me. Because He sees how happy I am being His sub. And that I don't punish myself by being His sub. Sometimes it still goes wrong. But my Master has to trust I will tell Him when something triggers me.

It's very important you can trust eachother. Everyone has his responsibilities, also the sub. It's the Dom's responsibility to care for his sub. But it's also a great responsibility and for some subs also a great task not to use your Dom to feel worthless.